Universal tank stage



Feb. 28, 967 J. B. 6038 3,306,396

UNIVERSAL TANK STAGE Filed July 22, 1964 3 Sheets-Sheet l 1/0/20 19. GOJJ INVENTOR.

W M M Feb. 28, 1967 @055 3,3Q6,396

- UNIVERSAL TANK STAGE Filed July 22, 1964 5 Sheets-Sheet 2 L l I (/06/7 19. .60JJ INVENTOR.

BY wwz/ Feb. 28, 1967 J 055 UNIVERSAL TANK STAGE 3 SheetsSheet Filed July 22, 1964 J J 0 6 5 0 0 a IN VEN TOR.

United States Patent 3,306,396 UNIVERSAL TANK STAGE John B. Goss, 2606 Knoblock, Houston, Tex'. 77023 Filed July 22, 1964, Ser. No. 388,971 5 Claims. (Cl. 182-428) The present invention relates to new and useful improvements in tank stages or platforms and particularly to a universal tank stage for use inside of a tank having various inner shapes or configurations.

It can be appreciated that in cleaning and painting the inside of large storage tanks, suchas those used in refineries or chemical plants and the like, having an inside diameter or breadth of fifty or sixty feet or more, it is desirable, and in some instances necessary, to position the workers within arms reach of the inner surface of the tank. In spherical or spheroidal tanks, the problem of providing a satisfactory support, which will support the painters or workers within the necessary proximity of the inner surface of the tank which is being painted or cleaned, is unusually severe.

In the past, temporary scaffolds have been erected or constructed inside of the tanks to enable workmen to safely reach the inner surface. and inconvenience of constructing a temporary scaffold in a tank having a generaly spherical or spheroidal configuration can be readily appreciated, especially when it is understood that access to the inside of such tanks is generally provided through relatively small manholes that are normally located in the top or bottom of such spherical or spheroidal tanks.

Therefore, an object of the present invention is to provide a new and improved universal tank stage for supporting a worker at substantially any desired location inside of tanks having spheroidal, spherical or other internal configurations.

An important object of the present invention is to provide a new and improved tank stage for conveniently and rapidly moving a worker about from one desired location to another in the interior of a tank or vessel.

Another object of the present invention is to provide a new and improved tank stage which is particularly suitable for use in a tank having limited access to the interior thereof.

Still a further object of the present invention is to provide a new and improved universal tank stage which can be temporarily erected in tanks of various configurations with a minimum of time and effort and which may also be quickly and easily removed from such tanks.

Another object of the present invention is to provide a new and improved tank stage for use in tanks having various configurations, which stage may be readily moved from one tank. to another, whether of the same or different sizes, so that the stage of this invention obviates the need for the temporary scaffolds heretofore used in tanks.

Yet another object of the present invention is to provide a new and improved universal t-ank stage comprising a substantially vertically disposed rotatable support member having a movable support member adapted to be moved longitudinally thereof with a telescoping boom mounted on said movable support member for positioning and supporting a worker at a desired location in the tank.

Still another object of the present invention is to pro-' vide a new and improved universal tank stage having a longitudinally extending support member which is normally disposed substantially vertically in a tank and having a boom pivotally mounted thereon which is adapted to be positioned at a desired location in a tank.

However, the difficulty Another object of the present invention is to provide a new and improved universal tank stage including a longitudinally extending cable adapted to be positioned in a substantially vertical position in a tank and having means for tensioning the cable and means for pivotally mounting a boom thereon whereby a carriage or basket adapted to carry a worker may be positioned in various desired locations in the tank.

It is also an object of the present invention to provide a new and improved universal tank stage having a pivotally mounted telescoping boom for carrying a basket or bucket which is adapted to support a worker at substantially any desired location in tanks of various configurations.

Yet a further object of the present invention is to provide a new and improved universal tank stage for use in a spherical or spheroidal tank including a substantially vertically extending rotatable support member, a movable support movable longitudinally with respect to the vertically disposed support member and a telescoping boom pivotally mounted on said movable support for supporting a worker in various desired locations in such tank.

Still a further object of the present invention is to provide a new and improved tank stage for use inside of a tank comprising a substantially vertically extending support or stand having a telescoping boom pivotally mounted thereon for supporting a worker in various desired locations in a tank.

The preferred embodiment of this invention will be described hereinafter, together with other features thereof, and additional objects will become evident from such description.

The invention will be more readily understood from a reading of the following specification and by reference to the accompanying drawings form a part thereof, wherein an example of the invention is shown, and wherein:

FIG. 1 is a view partly in elevation and partly in section showing one embodiment of the apparatus of the present invention disposed in a spherical tank and supporting a worker therein;

FIG. 2 is a view partly in section and partly in eleva-' tion showing an alternate embodiment of the apparatus of the present invention supporting two workers in a spherical tank;

FIG. 3 is an elevation showing details of construction of the top bracket and sheave support of this invention;

FIG. 4 is an isometric view showing details of construction of the telescoping boom and yoke for supporting a work-ers support basket in the present invention; and

FIG. 5 is a view partly in section and partly in elevation showing another embodiment of the apparatus of the present invention.

In FIG. 1 of the drawings, the universal tank stage of the present invention is designated generally by the letter A. As shown, such universal tank stage A comprises a longitudinally extending support member S which is normally disposed in a substantially vertical position in a storage tank or other large tank or container T and secured thereto, as will be described more fully hereinafter. A movable support R is carried on the longitudinal support S and is adapted to be moved circumferentially as well as longitudinally relative to such support S. A boom means B, which is shown mounted on the movable support R and which has a stage or carriage K thereon, is provided for supporting the stage K and positioning it at various desired locations in the tank T as will be explained more fully hereinafter. With the universal tank stage of this invention, a carriage or stage K can be positioned at substantially any desired location in a spherical or spheroidal tank of other container T, or in tanks having various other inner shapes or configurations, and may be quickly and easily moved about from one desired location to another, as desired.

Considering now the apparatus A of this invention in more detail, the stand or Vertical support member S is normally disposed substantially vertically in the tank T with the upper end 14 of the shaft S extending through an upper manhole 15 and the lower end 16 extending through a lower manhole 17 in the tank T. The upper end 14 of the stand S. is normally secured to a suitable projection 19, such as an annular wall surrounding the manhole 15 or some other suitable means adjacent the manhole 15, by securing means 20 such as a chain or cable. As shown, a bracket 20a is provided for securing the chain 20 to the stand S. Similarly, the lower end 16 of the stand S normally has a securing chain or cable 21 connected thereto by means of a bracket 21a or other suitable means. The cable 21 is anchored to the support legs 25 of the tank T or to some other suitable anchoring means, as desired.

As shown, the stand S rests on a suitable support block or plate 16a which is normally disposed on the ground G. However, if a suitable manhole is not provided at the bottom of the tank T or, if for other reasons, it is desired to support the stand S in the tank T, the lower end 16 of the stand S may be disposed inside of the tank T and allowed to rest on a suitable plate or support block 16a at the bottom of such tank T, as desired.

The stand S may comprise a single longitudinal member or, if desired, such stand may include a plurality of sections which are threaded together or otherwise suitably connected together to form the longitudinally extending shaft or support stand S.

The movable support R normally comprises a longitudinally extending tubular member which encircles the shaft or stand S and which is adapted to be moved longitudinally relative thereto and also to be rotated thereon, as will be explained herein. Such movable support normally has pivot means mounted thereon for pivotally mounting the boom B. Such pivot means 30 normally includes a bracket 31 for receiving a pivot pin 32 which extends laterally through the boom arm B.

As shown in FIGS. 1 and 4 of the drawings, the boom B is preferably expansible and normally includes an outer member 35 and an inner member 36 which preferably fits telescopically within such outer member 35 thereby allowing the length of the boom B to be expanded or contracted to a desired length. As best seen in FIG. 4, the outer member 35 has one or more openings 35a formed therein with corresponding openings 36a formed in the inner member 36 and which are adapted to be aligned with such openings 35a to receive a pin 37 or other suitable securing means to lock the telescoping members 35 and 36 in a desired position relative to each other. A stage support member or yoke 40 is normally connected to the outer end of the boom B and has pivot pins 40a in opposite sides thereof for supporting a stage or carriage K, which is provided for carrying a workman W and for positioning such workman relative to the inside of the tank for painting or sandblasting such tank. It will be appreciated that the carriage or stage K may be a basket or bucket type of enclosure shown in FIG. 4 of the drawings, or, any other suitable type of chair or support means may be provided for supporting the workman W on the boom B. Or, if desired, the carriage K may be eliminated and the sandblasting or paint spraying equipment or the like mounted directly on the end of the boom B.

It is understood that in positioning the end of the boom B in the tank T and in moving such boom B from one position to another, the movable support R will be moved longitudinally relative to the stand S and the boom B will be pivoted relative to such support R. To accomplish these separate movements, separate cable and sheave arrangements are provided in the preferred form of the present invention; however, it can be appreciated that other suitable means may be provided for moving the support R and pivoting the boom B, without departing from the scope of the present invention.

As seen in FIG. 1 of the drawings, a sheave support 45 is provided near the upper end of the shaft or stand S for carrying sheaves 46 and 46a. As best seen in FIG. 3 of the drawings, the sheave support member 45 is rotatably mounted on the shaft or stand S by means of a laterally extending member such as a pipe clamp 47 or other suitable means which may be secured to the stand S by means of bolts 47a or other suitable securing means, as desired. A th rust washer or bearing 48 is preferably provided between the support or clamp 47 and the sheave support arm 45 to facilitate free rotation of such support arm 45 relative to the shaft S. The sheaves 46 and 46a are normally connected the support bar 45 by means of a flexible connection 49 such as a pair of shackles, or the like, for a purpose to be described hereinafter.

In the preferred form of the present invention the movable support R may be elevated or moved longitudinally upwardly relative to the shaft or stand S by means of a flexible line 50 which has one end 50a connected to the movable member R and whose lower end extends downwardly through the opening or manhole 17 in the lower part of the tank T where such cable is normally connected to a cleat or pin 48. Such flexible cable or chain 50 extends over the sheave 46 near the upper end of the shaft or stand S thus enabling the movable support R to be moved longitudinally upwardly along the shaft S by moving or pulling the cable 50 downwardly through the manhole opening 17 and longitudinally downwardly by releasing the cable 50. Such cable 50 may comprise a rope or chain or by means of a winch (not shown), as desired.

Similarly, the boom B may be raised and lowered by means of a flexible cable or rope 51 which has one end 51a anchored or fixed. As shown in the drawings, the end 51a of the cable 51 is secured to the sheave support 45 with the other end of the cable 51 extending downwardly through the manhole opening 17, where such cable or rope 51 may be connected to the pin or cleat 48 on the shaft or stand S. The rope or cable 51 is normally drawn around a sheave 52 which is normally rotatably mounted on the outer end of the boom B (FIG. 4), and the cable 51 is also drawn around the sheave 46a to facilitate raising and lowering such boom B by someone standing on the ground G or positioned therebelow either in the tank T, or out of the tank, as desired.

It will be appreciated that the sheave and line arrangement shown herein is for purposes of illustration and description and that various other arrangements of sheaves and lines may be provided for raising and lowering the boom B and also for raising and lowering the movable support R relative to the stand or shaft S without departing from the scope of the present invention. Also, it can be appreciated that such boom B may be pivoted relative to the movable support R and such movable support R may be moved longitudinally relative to the shaft or stand S by other suitable moving means such as hydraulic pistons and the like without the use of lines and sheaves without departing from the scope of this invention.

Also, it should be noted that, as shown in the drawings, the movable support or sleeve R with the boom B and the carriage K supported thereon, is rotated about the shaft or stand S by urging the line 51 laterally relative to the support arm 45 in the desired direction of rotation. The flexible support or connecting shackle 49 on which the sheave 46 is carried, allows the sheave 46 to be urged laterally with little risk of their laterally displacing the cable 51 from the sheave 46a.

In using the apparatus A as shown in FIG. 1 of the drawings for positioning a workman W at substantially any desired location in a spherical or spheroidal tank or cylindrical tank, as desired, the stand or shaft S is normally positioned in the tank T in a substantially vertically extending position. Such apparatus A may be inserted longitudinally into the tank T in a single preassembled unit or, if preferred, the shaft or stand S, the movable sleeve R, the boom B, the stage or carriage K may be inserted separately or individually through either of the manhole openings 15 or 17 and thereafter assembled in the tank T.

After the stand or shaft S has been secured in a substantially vertically extending position as shown in FIG. 1 of the drawings with the movable sleeve R mounted thereon and with the boom B pivotally mounted on such movable support R, the lines or cables 50 and 51 may be rigged as shown in FIG. 1 of the drawings to thus prepare the temporary stage or workers support A or use in the tank T.

With the apparatus A thus arranged, the worker W may amount the stage or carrier K which may thereafter be positioned at a desired location relative to the inner surface of the tank T by manipulations of the lines 50 and 51. This is preferably accomplished by someone standing on the ground near the manhole opening 17 who may manipulate the ropes 50 and 51 to elevate the movable sleeve R to the desired elevation and to thereafter pivot the boom B upwardly or downwardly relative to such movable support R and to rotate such support R relative to the stand S to position the worker in the desired location in the tank T.

As shown, the expansible or telescopic boom B may be expanded to a predetermined or desired length and thereafter locked in such position by means of a locking pin 37 (FIG. 4) and thereafter such boom B will maintain a substantially fixed radius until the locking pin 37 is removed and the shafts 35 and 36 telescope relative to each other to either extend or retract the boom B. However, it can be appreciated that such boom B may be expanded or retracted by other suitable means such as a hydraulic cylinder and piston or by means of a suitable rack and screw arrangement, or other suitable means, without departing from the scope of the present invention.

Also, as shown in FIG. 1 of the drawings, a fluid supply hose or conduit 80 may be secured to the boom B to facilitate sandblasting or spray painting the interior surface of the tank T. The lower end of the hose 80 may extend through the manhole 17 to sandblasting or painting equipment on the ground G or such equipment may be disposed in the tank T.

With the apparatus A thus disposed in a tank T, the movable support R and the boom B as well as the sheave support 45 may be rotated about the shaft or stand S to position the stage or carriage K containing the worker W in substantially any desired position circumferentially of the tank T. Also, the boom B may be elevated or depressed by means of the line 51 to raise or lower the stage or bucket K containing the worker W to position the worker W at substantially any desired elevation in a tank T. Thus, it can be appreciated that with the apparatus A of this invention as shown in FIG. 1 in the drawings the worker W or the end of the boom B may be positioned at any desired proximity or distance relative to the wall of the tank T whether the tank T be spheroidal, spherical, cylindrical or of various other configurations to facilitate sandblasting, painting or inspecting of the surface of such tank T. Also, it can be appreciated that the apparatus A may be quickly and easily installed or assembled in the tank T and removed therefrom for re-use at a later time or in another tank, as desired.

Considering next another embodiment of the apparatus of the present invention as illustrated in FIG. 2 of the drawings, it will be seen that the stand or support S comprises a flexible cable C. As shown in FIG. 2 of the drawings, the flexible cable C is connected at its opposite ends to a movable support R to form a substantially endless loop support designated generally 8-1.

As shown, the cable C is drawn or looped over an upper cable support means or sheave 60 and a lower cable sup port means or sheave 61, which are disposed oppositely relative to each other in the tank T. The opposite ends 62 and 63 of such cable C are connected to opposite ends of the movable support member R by means of eyebolts and cable clamps 64 or other suitable connecting means.

The upper sheave or cable member 60 is normally supported on a support chain or cable or other suitable support member 65 which, as shown, is preferably connected to a cable support member 66. Such upper support member 66 normally extends diametrically across the upper manhole opening 15 and rests on the annular flange or shoulder 15a extending circumferentially of such manhole opening or, the support 66 may rest on the tank T. As shown, the upper support member 66 has a T shape with a ring or eyebolt 66a secured thereon for connecting the cable or other flexible support 65 thereto, and to align the support chain 65 and the apparatus depending therefrom substantially axially of the tank of container T. However, the upper support 66 may be formed of a shaft or plate adapted to extend across the manhole 15, as desired. Also, swivel means 67 is normally provided in the support chain or cable 65 for a purpose to be described more fully herein. 7

The lower sheave 61 is shown mounted in a sheave support bracket 62 which is connected by means of a flexible support cab-1e or chain 63 to a cable support member 68 which, as shown is similar to the T-shaped cable support member 66 as described herein. However, the cable support'member 68 may comprise a longitudinally extending bar or rod or other suitable member for engaging the annular shoulder 17a extending around the lower manhole opening 17. A swivel 69 or other suitable rotatable member which is similar to the swivel 67 is provided in the support chain or cable 63 which cooperates with the upper swivel 67 to enable the endless loop support S1 and the sheave or cable support members 60 and 61, respectively, on which such endless cable loop S1 is carried to be rotated about the longitudinal axis of such endless loop S1 for a purpose to be described more fully hereinafter.

A turnbuckle or other suitable tensioning device 70 is preferably provided in the lower support chain or cable 63 to enable the endless loop cable C to be placed in tension for supporting the movable support R in a substantially vertical position in the tank T. Also, a crank or other suitable rotating means 61a is shown connected to the lower sheave 61 to facilitate rotation of such sheave 61 to move the flexible endless cable loop S-1 for the purpose of raising and lowering the movable support R mounted thereon.

As shown in FIG. 2 of the drawings, a pair of stages or worker support baskets K are shown pivotally mounted on the movable support R by means of pivotally mounted telescopic booms B which are substantially identical to the boom B described hereinabove. A sheave support 45 is shown connected to the lower end of the upper support chain 65 by means of an eyebolt 65a or other suitable securing means. Sheaves 46a and 46 are connected to such sheave support 45 by means of shackles 49 or other suitable movable securing means as described hereinabove. Also, fall lines 31 are shown rigged on the sheaves 46a and also on the sheaves 52, which are secured to the expandible booms B, as described hereinabove to enable each of the support stages or buckets K to be raised or lowered independently of the other. It will be appreciated that one or more such stages or supports K may be used on this or other embodiments of this invention without departing from the scope thereof.

In using the embodiment shown in FIG. 2 of the drawings, the endless loop cable S-1 may be supported on the sheaves 60 and 61, respectively and connected to the movable support member R before such apparatus is inserted through one of the manholes 15 or 17 into the tank T, or, if preferred, the endless cable loop S-l may be connected or assembled in the tank T. After connecting the sheave assemblies 60 and 61 to the support chains or cables 63 and 65, respectively, the cable support members 66 and 68 may be positioned adjacent the manholes 15 and 17, as shown. Thereafter, the turnbuckle 70 is tightened to place the endless loop cable S1 in the desired tension for supporting the movable support R in a substantially vertical position. Then, with one or more boom members B pivotally mounted on such movable support R and with the fall lines 51 rigged through the proper sheaves 46a and 52 for each boom B, the apparatus of the present invention will be in operable condition. Thereafter, the workers W may mount their stages K and thereafter be positioned at the desired location in the tank T by manipulation of the fall lines 51 and the crank 61a which is provided for moving the movable support R longitudinally upwardly and downwardly, as desired. With the endless cable support S1 disposed between the upper swivel 67 and the lower swivel 69, the stages or cages K may be rotated about the inner surface of the tank T either by manipulation of the cable or rope 51 as described hereinabove, by applying force in a horizontal direction to the crank 610, or by other means, as desired.

Another embodiment of the apparatus of the present invention is illustrated in FIG. of the drawings. As shown in FIG. 5, a flexible support member, such as a cable or chain S-Z extends longitudinally of the tank T and has its opposite ends 70 and 71, respectively, secured to upper and lower cable support members 70a and 71a, respectively. Such support members 70a and 7111 may comprise longitudinal bars or rods adapted to extend across the manhole openings and 17, respectively, or such cable support members 70a and 71a may have substantially the same T-shaped configuration as the cable supports 66 and 68 shown in the FIG. 2 embodiment of this invention or, other suitable cable support means may be provided, as desired. A turnbuckle 75 is preferably provided near the lower end of such flexible support cable S2 to enable the cable to be placed in tension for a purpose to be described herein.

A sheave support member 45 is normally rotatably mounted on the cable S2 near the upper end thereof for supporting sheaves 46 and 4611. As shown, a lock member 77, such as a cable clamp or the like, is provided near the upper end of the cable 8-2 for supporting the sheave support member 45 thereon. Also, in a preferred form of the present invention, a suitable thrust washer or hearing 78 is provided between the cable clamp 77 and the sheave support arm 45 to enable such sheave support arm 45 to be rotated thereon.

In FIG. 5 the movable support R normally comprises a longitudinally extending hollow body or tubular sleeve which encircles the taut cable S2 and which is adapted to be moved longitudinally relative thereto, as well as to be rotated thereon.

One or more booms B, which are substantially identical to the booms shown in the FIG. 1 embodiment, are pivotally mounted on the movable support R. Preferably each boom B has a sheave 52 mounted thereon for receiving a line 51 which passes around such sheave 52 and over a boom sheave 46a to facilitate pivoting of the boom B upwardly and downwardly, as desired. Similarly, a rope or chain or other suitable line 50 is normally connected to the movable support R and passes over another sheave 46 to facilitate raising or lowering the movable support sleeve R relative to the taut cable 8'.

In the FIG. 5 embodiment of the present invention, as is the case in the FIG. 1 and FIG. 3 embodiments hereof, one or more booms B may be mounted on a movable support R, as desired. Also, as shown in FIG. 5, guy wires or struts 79 may be provided on the movable support R for stabilizing such support.

In installing the FIG. 5 embodiment of the apparatus of the present invention, the cable S2 may be positioned in the tank T as shown in the drawings with the upper end 70 connected to the cable support 70a and the lower end 71 connected to the cable support member 71a and with the cable S2 placed in the desired amount of tension by means of the turnbuckle 75 for maintaining the movable support R in a substantially vertical position. As in the case of the FIG. 1 and FIG. 2 embodiments of the apparatus of the present invention, the movable support member R may be moved longitudinally upwardly and downwardly by manipulation of the line or cable 50 and also, such line 50 may be used for moving the cage or carriage K circumferentially relative to the cable 8-2 and the tank T. Similarly, the boom B may be pivoted upwardly and downwardly by means of the line or cable 51 and the sheaves 46 and 52 around which such cable is drawn.

The foregoing disclosure and description of the invention is illustrative and explanatory thereof and various changes in the size, shape and materials, as well as in the details of the illustrated construction, may be made within the scope of the appended claims without departing from the spirit of the invention.

What is claimed is:

1. A tank stage for providing a working support for use inside of a tank comprising:

(a) a support member disposed wholly within the tank and extending longitudinally in the tank,

(b) means including a cable disposed within the tank and connected to said support member for supporting said support member in such longitudinally extending position,

(c) boom means pivotally mounted on the longitudinally extending support member,

(d) stage means on said boom means,

(e) means for pivoting said boom means relative to said support member, and

(f) means within the tank for mounting said cable for movement to lift and lower said support member and the boom means therewith relative to the tank.

2. The structure set forth in claim 1, including:

(a) means for mounting said boom means for rotation within the tank.

3. A tank stage for providing a working support for use inside of a tank comprising:

(a) longitudinally extending support means disposed substantially vertically in a tank,

(b) a movable support member carried on said longitudinally extending support means and adapted to be moved longitudinally relative to said support means in the tank,

(c) means for raising and lowering said movable support member relative to said support means,

(d) boom means pivotally mounted on said movable support member,

(e) means for pivoting said pivotally mounted boom means, and

(f) stage means supported on the free end of said boom means for supporting a worker whereby said worker may be positioned at any desired location in the tank by moving the movable member and pivoting the pivotally mounted boom means on which the stage is supported.

4. A universal tank stage support means for supporting a working stage in a tank, including:

(a) an endless flexible support member,

(b) a plurality of rotatable support means for supporting said flexible support member,

(c) a substantially rigid longitudinally extending element carried on said endless flexible support member,

((1) boom means pivotally mounted on the rigid element, and

(e) stage means on said boom means adapted to support a worker adjacent the inner surface of a tank.

5. A universal tank stage support means for supporting a working stage in a tank, including:

(a) an endless flexible support member,

(b) a plurality of rotatable support means for supporting said flexible support member,

(c) a substantially rigid support member carried on said endless flexible support member and adapted to extend longitudinally of the tank,

(d) boom means pivotally mounted on said rigid support member,

(e) means for extending said boom means,

(f) means for pivoting said boom means, and

(g) stage means on said boom means for supporting a worker in a tank.

References Cited by the Examiner UNITED STATES PATENTS Johnson 182-128 X Weasler 182128 Myers 182128 Reeves 1822 X Brock 182-2 Verrell 1822 France.

REINALDO P. MACHADO, Primary Examiner. 

1. A TANK STAGE FOR PROVIDING A WORKING SUPPORT FOR USE INSIDE OF A TANK COMPRISING: (A) A SUPPORT MEMBER DISPOSED WHOLLY WITHIN THE TANK AND EXTENDING LONGITUDINALLY IN THE TANK, (B) MEANS INCLUDING A CABLE DISPOSED WITHIN THE TANK AND CONNECTED TO SAID SUPPORT MEMBER FOR SUPPORTING SAID SUPPORT MEMBER IN SUCH LONGITUDINALLY EXTENDING POSITION, (C) BOOM MEANS PIVOTALLY MOUNTED ON THE LONGITUDINALLY EXTENDING SUPPORT MEMBER, (D) STAGE MEANS ON SAID BOOM MEANS, (E) MEANS FOR PIVOTING SAID BOOM MEANS RELATIVE TO SAID SUPPORT MEMBER, AND 